PDF - Wallace Online

COLOURS OF ANIMALSthat "it is so bold that the sight of man creates no alarm."The beautifully-coloured Thaumastura cora "rarely permitsany other humming-bird to remain in its neighbourhood, butwages a continual and terrible war upon them." The magnificentbar-tail, Cometes sparganurus, one of the most imposingof all the humming-birds, is extremely fierce and pugnacious," the males chasing each other through the air with surprisingperseverance and acrimony." These are all the species I findnoticed as being especially pugnacious, and every one of themis exceptionally coloured or ornamented, while not one ofthe small, plain, and less ornamental species are so described,although many of them are common and well observed species.It is also to be noticed that the remarkable pugnacity of thesebirds is not confined to one season or even to birds of thesame species, as is usual in sexual combats, but extends to anyother species that may be encountered, while they are saideven to attack birds of prey that approach too closely totheir nests. It must be admitted that these facts agree wellwith the theory that colour and ornament are due to surplusvital energy and a long course of unchecked development.We have also direct evidence that the males are more activeand energetic than the females. Mr. Gosse says that thewhirring made by the male Polytmus humming-bird is shrillerthan that produced by the female and he also informs us;that the male flies higher and frequents mountains, while thefemale keeps to the lowlands. 1Theory of Normal ColoursThe remaining kinds of animal colours, those which canneither be classed as protective, warning, nor sexual, arethe most part readily explained on the general principles ofthe development of colour which we have now laid down. Itis a most suggestivefact that in cases where colour is requiredonly as a warning, as among the uneatable caterpillars, wefind, not one or two glaring tints only, but every kind ofcolour disposed in elegant patterns, and exhibiting almost asmuch variety and beauty as amonginsects and birds. Yet1Some other cases are noticed at p. 317. For some further developmentsand illustrations of the theory of sexual colour, see Darwinism,chap. x.for